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Graduated Driver Licensing
Governors Highway Safety Association Annual Meeting 2017
Rebecca Weast, Ph. D.
Graduated Driver Licensing programs 1996 - 2017
New review of the literature (Williams, in press)
–Confirms: GDL reduces crash fatalities among younger teen new drivers
–Resolves Uncertain Findings: GDL participation does not increase fatalities
for older teens
Points to Next Steps in research and implementation
–Determine optimal calibration for GDL policies
–Apply strongest GDL standards across the board
–Apply GDL to all new drivers under age 21
What is GDL?
Graduated licensing components
Learner’s phase
Entry age
Supervised driving certification
Minimum duration
Intermediate phase
Entry age
Nighttime driving restriction
Passenger restriction
Minimum duration
Graduated licensing
is a 3-stage system beginning
with a learner’s stage of
supervised practice driving.
Full licensure is granted after
completion of an intermediate
stage that restricts driving
under high-risk conditions.
Fatal crashes per 100,000 people By driver age, 1996-2015
Since 1996, when the first
graduated driving licensing
program was implemented,
fatal crash rates have declined
more dramatically for
teenagers than for adults
0
10
20
30
40
50
1996 2000 2005 2010 2015
-74%
-61%
-55%
-45%
-29%
State evaluations of graduated driver licensing
In states where graduated
licensing laws have been
evaluated, there are
substantial reductions in
crashes for the
ages covered.
age
groups
crash
reductions
Florida 15-17 9%
Iowa 16-17 25-30%
Michigan 16 29%
New York 16 31%
North Carolina 16 23%
Ohio 16-17 23%
Wisconsin 16 14%
Changes in state licensing requirements 1995 vs. 2017
Since 1995 many
states have
strengthened teenage
licensing laws.
number of states
plus the District of Columbia
1995 April 2017
minimum learner’s age 16 or older 8 8 & DC
learner’s permit for at least 6 months 0 48 & DC
30+ hours of certified (supervised) driving 0 44 & DC
minimum intermediate license
age older than 16 3 11& DC
night driving restriction once licensed 9 49 & DC
passenger restriction once licensed 0 45 & DC
Effects of GDL
Effects of GDL on crashes by age
Age 16
–16% reduction in all crashes, 35% reduction in fatal crashes (Masten, Thomas, Korbelak,
Peck & Blomberg, 2015)
Age 17
–11% reduction in all crashes, 17% reduction in fatal crashes (Masten, Thomas, Korbelak,
Peck & Blomberg, 2015)
Ages 18-20
–GDL does NOT appear to have a negative impact on teen drivers after they
participate in the program
–Teens who went through GDL beginning at age 16 showed positive crash effects
for 3-5 years (Foss et. al. 2014)
–15 year study: GDL reduces crashes for 16 & 17 year old drivers, does not
increase crashes for 18 & 19 (Thompson, McGee & Feng, 2016)
Effects of GDL components
Learner Phase
– 6 months is better than 3 months (Ehsani, Bingham & Shope, 2013)
– 9-12 month duration yields the greatest crash reductions (Masten et. al. 2015)
– No clear evidence on the optimal amount of supervised practice driving
Intermediate Phase
– Adding passenger restrictions to GDL sharply reduces crashes for 16- and 17-year-old drivers
(32% and 15% respectively in NC study)
– Nighttime restrictions beginning at 9 or 10 p.m. reduce crashes for 16-year-old drivers by 7-8%
Percent reduction in teenage crashes per population from graduated licensing components
0 5 10 15 20
increasing minimum practice drivingby 20 hours
teen passengers limited to 0 or 1
9 pm night driving restriction
1-year delay in license age
1-year delay in learner's permit age
fatal crashes, 15-17 year-old drivers
collision claim frequencies, 16-17 year-old licensed drivers
Licensing laws that include
strong nighttime and
passenger restrictions, and
laws that delay the learner’s
permit and licensing age,
reduce teenage driver crash
involvements.
GDL challenges
GDL Challenges
GDL is inconsistently applied to young teens (16 and 17 year-olds)
Most states apply GDL to license applicants younger than 18, and lift probationary
license restrictions when teenagers turn 18
Many states begin nighttime restrictions later than is ideal
– Midnight or later, rather than 9 or 10 p.m.
States introduce fewer and fewer GDL laws every year
– 122 laws introduced in 2009, compared with only 30 bills in the last 12 months.
GDL Challenges States introduce fewer and fewer GDL laws every year, meaning fewer and fewer pass
Graduated license law calculator for states encourages even good states to improve
In 2012, IIHS introduced
an on-line calculator for
states showing potential
crash reductions from
strengthening five
licensing law components.
A “match the best” feature
shows the benefits of
matching the strongest
provisions for all five
components.
Moving forward
GDL next steps
There is strong evidence that GDL reduces crashes at ages 16-17, and the
concern about negative effects at ages 18-19 is unwarranted
States should be encouraged to improve their existing GDL programs
– There have been very few improvements since 2010
– Need nighttime restrictions beginning at 9 or 10 p.m.
– Need passenger restrictions that limit driver to zero teen passengers
Develop driver education and GDL programs that include greater parent
involvement
– Programs that change teen driver behavior require direct parent involvement
Determine the potential effects of GDL policies on older novices (age 21+)
Summary
GDL has been a major factor in reducing crash risk for the younger teens
Significant variation in GDL component strength indicates that progress still is
needed to minimize crash risk among young novices across the U.S.
– Existing GDL programs need to be improved
There is potential to reduce crash risk for older novice drivers
– Older novice drivers make up a large and diverse population
– Little is known about potential GDL effects for older novices
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Rebecca Weast, Ph.D Research Scientist [email protected]